1. Field of the Invention
This invention relates to an automatic exposure control means for a single-lens reflex camera, and more particularly to an automatic exposure control means in which both the shutter speed and the diaphragm are controlled to obtain the optimum combination thereof relative to the quantity of light passing through the taking lens of the single-lens reflex camera.
2. Description of the Prior Art
Various automatic exposure control means have been proposed for controlling the shutter or diaphragm of a single-lens reflex camera. Among these conventional automatic exposure control means, is an automatic exposure control means associated with an electric shutter. It has also been known in the art to control both the shutter speed and the diaphragm opening rather than to control one or the other of these. Control of this type is known as program type exposure control. Most of the program type exposure control means employing an electric shutter normally control both the diaphragm and the shutter by use of an electric circuit.
The above described program type exposure control means in which the diaphragm and the shutter are controlled by an electric circuit is disadvantageous in that the circuit is considerably complicated and various additional control means such as a magnet for controlling the diaphragm are required. Further, the above described program type exposure control means is not applicable to a single-lens reflex camera with a focal plane shutter, since the interconnection between the interchangeable lens and the camera body is very difficult.